The present invention relates to heart valve replacements. Replacements are required for patients whose own valves have begun to fail. While many heart valve replacements rely on combinations of tissue and mechanical elements, the creation of valves from tissue, including autologous tissue, without the use of a supporting assembly or stent is also known. Senning, for example, describes such a technique for replacing a diseased heart valve with one made from the patient's own tissue in the Journal of Thoracic and Cardiovascular Surgery at Vol. 54, p. 465-470 (1967). Senning employed a piece of the patient's untreated fascia lata to fashion a trileaflet valve and sutured the new valve to the patient's native valve remnant with a continuous suture, reinforced at the valve's commissures with pledgeted sutures.
While Senning and other surgeons recorded some notable successes with their stentless autologous-tissue heart valves, they quickly encountered several difficulties. These included shrinkage and calcification of the tissue comprising the replacement valve. Additionally, fabrication of autologous-tissue valves during cardiac surgery required great skill and could not be done rapidly. Consequently, the technique of using autologous tissue to fashion stentless heart valves was soon abandoned by most surgeons in favor of the use of glutaraldehyde-tanned, stent-mounted valves, or mechanical prostheses.
Exemplary embodiments of such bioprostheses are disclosed and claimed in U.S. Pat. No. 4,470,157 and 5,163,955 assigned to Autogenics, assignee of this application, which uses stent assemblies to support a piece of autologous tissue.